Antiperspirants are socially and cosmetically desirable products. Aluminum and zirconium chlorohydrates are Category I antiperspirant actives and products containing the same can be legally designated "antiperspirants". Other metal salts have been found to be effective, but have not found their way to the marketplace for many valid reasons. Anticholinergics, including scopolamine derivatives, are the most effective antiperspirants known. However, because of their poor skin-penetration properties, they require injections for effectiveness. Antiadrenergics have also been investigated, but have only developed academic interest. Aldehydes such as formaldehyde can suppress sweating, but their sensitization potential has eliminated commercialization. Metabolic inhibitors such as ouabain have been studied academically. Accordingly, at present, there is no really viable substitute for aluminum and zirconium chlorohydrates.
Antiperspirant compositions by definition must reduce or eliminate perspiration, at least in a designated area to which they are topically applied and, due to constant elevation of antiperspirant aims and objectives, are constantly increasing in their effectiveness, which by some standards must reduce perspiration by at least 20% in 50% of the population, although in many cases the attainment of such high percentage is not and may never be possible. Although numerous compositions have been proposed as antiperspirants, few of them have been successfully marketed because of their failure to provide effective antiperspirant relief or due to the production of irritation or other undesirable side effect and, after all these years, the most effective and successful antiperspirant compositions are still those comprising large proportions and amounts of aluminum or zirconium chlorohydrate or like mineral salts which retard the perspiration phenomenon, despite their frequently irritating nature and their undesirability from the standpoint of inherent toxicity.
Studies have been conducted and published concerning the anhydrosis effected by the application of various types of adhesive tape and tape-secured sheets of plastic to the skin and, although these investigations confirmed an anhydrosis effect, side-effects of an allergic nature as well as a mechanical nature and ensuing traumatic effects were also found to result. Moreover, in certain studies conducted on grants from the Army, the anhydrosis did not completely disappear and normal perspiration recover for a period of weeks after such application of the tape or plastic sheet for a period of only six (6) days. These studies, which seem mainly to have been directed at a determination of side effects of the procedure, did not in any event provide any effective measure or product for use as a topical antiperspirant, or apparently suggest any such preparation to those skilled in the art, over the period of approximately twenty-five years since appearance of the publications reporting the same. Specific identification of such known studies is as follows:
The first publication is entitled "Adhesive Tape Anhydrosis", by Gordon and Maibach, appearing in Arch. Derm. 100, 429-431 (October 1969), the study being supported by U.S. Army Research and Development Command, the earlier second reference being by Orentreich, Berger, and Auerbach, appearing in Arch. Derm. 94, 709-711 (December 1966), this publication being entitled "Anhydrotic Effects of Adhesive Tapes and Occlusive Film", and a third publication entitled "The Use of Partial Sweat Duct Occlusion in the Elucidation of Sweat Duct Function in Health and Disease", by Johnson and Shuster, J. Soc. Cosmet. Chem. 24, 15-29 (1973), which studied the effect of pressure due to occlusive tape on the sweat rate and the type of reabsorption involved, whether water or electrolyte. Nothing disclosed in those publications or suggested thereby comprises any part of the present invention, and reference is made thereto merely for purposes of completing the record. The innumerable publications and patents, which have appeared in the antiperspirant field since that date, attest to the fact that these publications did not change the direction of research in the field.
A search conducted in the antiperspirant classes, namely Class 424, Subclasses 65-68, 46, 47, Dig. 5 and IPC Class A61K7/32, turned up thirty (30) U.S. patents issued between 1978 and 1991, some of which included a polymer in the composition thereof, but only one of which consisted essentially of the polymer or relied upon the polymer to produce a desired antiperspirant effect. These developments employed the polymer merely as a means for adhering and/or maintaining the other chemical antiperspirant elements of the composition in contact with the skin of the human subject to which it was applied and in which an antiperspirant effect was desired to be attained, or relied upon an absorption phenomenon. Of all the patents turned up in the search, only U.S. Pat. Nos. 4,690,817, 4,743,440, 4,743,441, and 4,963,591 appeared to have any relevance to the present invention whatever.
The U.S. Pat. No. 4,690,817 patent related to the employment of polyvinyl alcohol polymers having pendant cationic quaternary nitrogen-containing groups to produce a film-forming moisture barrier for use in hair and skin conditioning compositions, which films were alleged to act as adhesives for the other composition components and as a partially impenetrable barrier to prevent loss of moisture by evaporation and to retain moisture through the formation of hydrates and no suggestion was made that such polymer or polymeric film would or could be useful as an antiperspirant per se.
The U.S. Pat. No. 4,743,440 patent related to antiperspirant products containing a moisture-absorbent non-film forming polymer instead of or in addition to the usual metal salt. The product was applied to the skin in a finely-divided powder form to give a dry, non-sticky deposit for absorbing skin moisture such as perspiration, the polymer being capable of absorbing an amount of moisture at least equal to its own weight after depositing the product onto the skin. The requisite characteristics of the polymer were that it be a non-film-forming polymer, and the composition comprised a non-aqueous liquid phase and a solid phase, as well as a propellant to produce an aerosol spray and a carrier other than a propellant for the organic polymer involved, the polymer involved in that case being a chemically-modified cellulose in particulate form, although polysaccharides, polypeptides, and vinylcarboxy polymers and copolymers were also mentioned as utilizable and numerous water-soluble and water-insoluble polymers were mentioned in Columns 3 and 4 of that patent as being suitable. Nothing is said in that patent concerning the occlusiveness of any polymer involved as having anything to do with its effectiveness as an antiperspirant, unless occlusiveness is equated with moisture absorbency, which it clearly is not in the present case.
U.S. Pat. No. 4,963,591 related to cellulosic polymer-solvent systems capable of dispersing a thin substantive film on the skin for cosmetic purposes and required the employment of a water-insoluble cellulosic ether for use in all kinds of lotions and creams designed for topical application, including deodorant and antiperspirant products, and alleged that the compositions of that invention could be applied to the skin wherever conditioning or treatment is desired by smoothing it over the skin, but made no claim whatever for the use of such films per se as an antiperspirant although it disclosed the employment of such polymers in sun screen-insect repellents and in solution in an aliphatic alcohol such as ethanol, propanol, or isopropanol along with other materials of an emollient nature and ordinarily employed in cosmetic preparations.
U.S. Pat. No. 4,743,441 disclosed the employment of a film-forming cosmetic composition as a facial pack, nail enamel, eyeliner, or the like comprising a copolymer of vinyl alcohol and alkyl vinyl ether, but made no claim to employment of such a composition per se or otherwise for antiperspirant purposes.
Additionally, U.S. Pat. No. 4,322,400, Yuhas; U.S. Pat. No. 4,985,547, Yano et al.; U.S. Pat. No. 5,025,004, Wu et al.; U.S. Pat. No. 5,039,516, Goodman et al.; U.S. Pat. No. 4,650,670, Callingham et al.; U.S. Pat. No. 4,673,571, Mahieu et al.; and U.S. Pat. No. 4,764,365, Boothe et al., have been called to my attention, but a study of the disclosures of these patents shows that they make no disclosure or suggestion of any topical antiperspirant composition consisting essentially of an effective amount of a non-toxic water-insoluble occlusive film-forming antiperspirant polymer in a topically-acceptable non-toxic medium, which is the subject matter of the present invention.
These prior-art teachings accordingly fall far short of the disclosure or suggestion of any concept of significance according to the present invention.
It is apparent that improved topical antiperspirant compositions have been the object of research over an extensive period, that the research has been mainly directed toward improved formulations of antiperspirant chemicals, that after all the years of research in this field mineral salts such as aluminum and zirconium chlorohydrates are still fundamentally relied upon for producing the desired antiperspirant effect of an antiperspirant composition or formulation in which they are present, and that efforts to eliminate the same from, or reduce the amount of the same in, the usual antiperspirant formulations have met with little if any success. Much less has any antiperspirant composition or formulation appeared on the scene which relied essentially upon the antiperspirant effect of a topically-applied non-toxic water-insoluble occlusive film-forming polymer, which is the essence of the present invention. It is also apparent that efforts to eliminate the undesirable mineral salts or reduce the quantity thereof necessary to produce a desired antiperspirant effect, or provide a viable alternative thereto, have been unsuccessful, and the present invention accordingly fulfills a long-felt need and shortcoming of the art, especially since the combined antiperspirant and deodorant market is now estimated at approximately 1.4 billion dollars per year.